Macintosh TV with no ADB

[d3jsp]

Got a Macintosh TV with no ADB inputs from either keyboard or mouse. Fuse F3 is fine and known good keyboard is getting 5V. Caps locks work slowly but all other locks just lights up and goes out instantly. Wondering if it's a break from the cuda chip.

Does anyone have schematics for the Macintosh TV or similar LC boards?

 

[d3jsp]

Seems like adb goes to pin 20 on the cuda just fine, what else could be broken further down

 

[d3jsp]

This is strange, don't see any obvious broken traces and the set clock modal gets instantly dismissed as soon as the OS boots so I wonder if something is being spammed on the line. The "didnt shutdown properly" modal stays though, always.

 

[d3jsp]

What should be the voltage on this ADB data line? I can't find any faults between ADB_IN, ADB_OUT and the port and am starting to suspect a faulty Q1 since I am only getting around 0.3 V on the data line. Should it be around 4.2-4.3v?

Also reflowed cuda and don't see anything obvious there

 

[d3jsp]

Swapped Q1 for a known good bt3904 from a working LC550 board and now it won't boot at all, no chime, just grey screen. ADB_IN, ADB_OUT does have ~4.x V though. I thought these were the same transistors